The present invention relates to a method and apparatus for monitoring stored chemicals.
It is sometimes necessary to store chemical compositions that are sensitive to heat, moisture, and pressure, as well as chemicals that are volatile or subject to degradation, for long periods of time. The physical or chemical condition of the chemicals can be monitored by testing samples of the chemical, but such sampling is time consuming, wastes materials, and is sometimes risky.
Nevertheless, for quality assurance, safety, and other reasons, it is important to know when chemicals, such as fertilizers, rocket fuels, and explosives, are or have been overheated, decomposed, contain too much moisture, or are subjected to other undesirable conditions. In some instances, it is not practical to break open the containers and sample the chemicals to determine their condition.
Accordingly, it is a goal of this invention to create a method and apparatus for quickly and accurately determining the condition of a chemical composition while the chemical composition is in a sealed container.
Other objects of the invention will be apparent from the following description and claims.
Systems for monitoring vehicle tire pressure and the like have been proposed wherein a transmitter and a receiver are mounted on a vehicle body, and magnetically coupled inductor and enhancer circuits are carried on the vehicle wheel to provide monitoring a vehicle tire pressure, as described by Allen in U.S. Pat. No. 4,588,978. Other devices to monitor tire pressure have been proposed by Galasko et al., in U.S. Pat. No. 4,578,992, who teach a coil mounted in a tire which forms, with a capacitor, a passive oscillatory circuit. The circuit is energized by pulses supplied via a coil positioned outside the tire and secured to the vehicle, and the frequency in the passive oscillatory circuit is varied with tire pressure due to changes caused to the capacitance value of the capacitor. The frequency in the circuit is sensed by a coil positioned outside the tire and secured to the vehicle.
Milheiser, in U.S. Pat. No. 4,730,188, teaches the use of a passive integrated transponder which is attached to or imbedded in an item to be identified, and is excited by an inductive coupling from an interrogator.
Fiorletta, in U.S. Pat. No. 5,289,160, teaches a wireless tire pressure monitoring system European Patent Application (EPA) 0312168 teaches a method and apparatus for electronically identifying articles moving along a surface, especially where the surface and/or articles comprise conductive material. The article is fitted with electronic responders, and the surface is provided with electrodes of a transceiver device. When the responders are located opposite the electrodes, a signal is sent.
EPA 0812,752 relates to an electromagnetic transmission and detection system comprising a transmission coil for producing a high intensity magnetic field, and first and second receiving coils for receiving a low intensity magnetic field from an inductively powered transponder. A ferrite rod is used to resonate the same operating frequency so that the energy transferred between the transmitter and the transponder is maximized.
PCT application WO91/07736 teaches a high temperature monitor that can be used near conductive objects that produces unwanted reflected impedance, and can be used to monitor the temperature within soup cans, and the like.
PCT application WO04/27117 teaches a security system which uses a container that has sensors for predetermined physical stimuli, for example a pressure sensor. The container contains a transponder for transmitting data from the sensor without opening the container.
A method of monitoring physical parameters of a composition enclosed in a container comprises the steps of (a) embedding a id-tag/sensor (transponder) in a composition wherein the sensor is capable of measuring physical parameters of the composition, (b) enclosing the composition in a container, (c) winding an antenna around the container in the proximity of the sensor, (d) bringing a communication means into proximity to the antenna, and (e) activating the sensor through the antenna using the communication means, and receiving and recording a response from the sensor using the communication means.
A ferrite core may be associated with the sensor for amplifying signals to and from the sensor.
Further, the physical parameters measured may be selected from the group comprising-pressure data, temperature data, moisture content data, chemical data and mixtures thereof.
The sensor may be enclosed in a loop of wire, wherein the sensor is electrically coupled with the wire to form a coupled sensor, a second wire may be placed adjacent to the is coupled sensor, and an antenna may be placed adjacent to the second wire.
In an alternative embodiment, the method may comprise the steps of (a) embedding an E-field sensor in a chemical composition, the E-field sensor being capable of measuring physical parmeters of said chemical composition, (b) enclosing the composition in a container, (c) placing an E-field antenna at opposed sides of the container, (d) creating an E-field in the antenna using an E-field driver to induce a signal in and receive a signal from the sensor, (d) bringing an E-field reader into proximity to the antenna, and (e) receiving and recording a response from the sensor.
In the methods, the receiving antenna may be placed inside or outside the container, it being important only that the receiving antenna be in close proximity to the transponder.
Also provided is a container for containing a chemical composition, the container comprising (a) impenetrable materials completely enclosing an interior space and having an inside and an outside, (b) an id-tag/sensor disposed inside the container, the id-tag/sensor being capable of retaining identification information and measuring physical or chemical parameters of the interior space, and an antenna associated with the sensor.
The antenna may comprise at least two loops of wire, a first wire being disposed in the proximity of the impenetrable material of the container and the sensor, and a second wire being disposed around the container. The first wire may be inside or outside the container. The first wire is used as a receiving antenna and the second wire is used as a transmitting antenna for the id-tag/sensor, and the id-tag/sensor is activated by communication means associated with the transmitting antenna.
The sensor may be a ferrite core pressure and temperature sensor having id information associated therewith, and the impenetrable material of the container may be a metal or a nonmetal.
In an alternative embodiment, the sensor may be in proximity to and coupled to a loop of wire disposed in the proximity of the impenetrable material of the container, and the loop of wire may be inductively associated with an antenna outside the container.
In another alternative embodiment of the container, the id-tag/sensor may comprise a chip sandwiched between an upper electrode and a ground electrode wherein the sensor is activated by at least two E-field plates at opposed sides of the id-tag/sensor. A first E-field plate may comprise a metal core in the interior of the container, and a second E-field plate may comprise the impenetrable material of the container. Alternatively, a first E-field plate may comprise a flat metal upper plate disposed on -a first side of the container, and a second E-field plate may comprise a flat metal ground plate disposed on a second, opposed side of the container.